Physiological Response Of ADC Trangenic Fan Flower’Dream Blue’under Cold And Drought Stress

In this paper, non-transgenic fan flower (S. aemula ’Dream Blue’) plants and ADC transgenic fan flower (S. aemula’Dream Blue’) plants obtained in our laboratory were used as researching materials to research the physiological response of ADC transgenic ’Dream Blue’ under cold and drought stress. Changes of the physiological and biochemical indexes of the two kinds of plants under cold and drought stress were tested, the performance under outdoor low temperature and the recovery after overwinter outdoors of the two kinds of plants were observed. Main results were as following:(1) Compared with non-transgenic plants, the transgenic plants grew more upright and less creeping; their stems were stouter; their stem inter-nodes length became shorter; their leaves were much bigger and thicker.(2) Adaptability under outdoor low temperature and recovery in greenhouse:in the first two weeks, most of the transgenic plants were slightly damaged, non-GM plants showed no significant frozen damage; in the two weeks afterwards, the frozen damage index of transgenic plants was slightly lower than that of non-GM plants; during the recorvery period in greenhouse, the transgenic plants recovered were more than the non-GM plants recovered.(3) Under indoor simulating cold stress, relative water content of both transgenic and non-GM plants decreasd "slow-fast-slow", while the chlorophyll content of the two kinds of plants decreasd "slow-fast". The transgenic plant had smaller increase in MDA content and relative electric conductivity than non-GM plant, indicating that the membrane of transgenic plants showed delay damage compared with the non-GM plants. The activities of SOD and POD of transgenic plants were both higher than that of non-GM plants. The SOD activity of transgenic plants and non-GM plants increased at first and then decreased apparently, POD activity droped dramatically at first and then rose slowly. The enzyme activity in transgenic plants maintained a high level which indicated that the combine of SOD and POD eliminated oxygen free radicals. ADC gene promoted the two enzymes’ activity expression in the face of adversity. The soluble protein content in ADC-GM and non-GM fan flower increased slowly and then drops dramaticaly, the former was lower, which indicated that the ADC gene expression was independent to soluble protein.(4) Soil relative water content gradually decreased under drought stress. The relative water content and chlorophyll content in both transgenic plants and non-GM fan flower showed a downward trend, the former decreased less. The relative electric conductivity in transgenic plants and non-GM plants increased in the trend of "slow-fast-slow". MDA content rised in the trend of "slow-rapid", and that of former rised less. The SOD activity, POD activity and soluble protein content in ADC-Transgenic plants and non-GM plants showed downward trend at first and then increased.